--- a/doc/interpreter/plot.txi	Sat Sep 30 14:53:30 2017 -0500
+++ b/doc/interpreter/plot.txi	Thu Jul 14 22:24:05 2016 -0700
@@ -466,6 +466,8 @@
 
 @DOCSTRING(campos)
 
+@DOCSTRING(camorbit)
+
 @DOCSTRING(camroll)
 
 @DOCSTRING(camtarget)

--- a/scripts/help/__unimplemented__.m	Sat Sep 30 14:53:30 2017 -0500
+++ b/scripts/help/__unimplemented__.m	Thu Jul 14 22:24:05 2016 -0700
@@ -575,7 +575,6 @@
   "camdolly",
   "cameratoolbar",
   "camlookat",
-  "camorbit",
   "campan",
   "camproj",
   "categorical",

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/plot/appearance/camorbit.m	Thu Jul 14 22:24:05 2016 -0700
@@ -0,0 +1,279 @@
+## Copyright (C) 2016 Colin B. Macdonald
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## This software is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty
+## of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public
+## License along with this software; see the file COPYING.
+## If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {} {} camorbit (@var{theta}, @var{phi})
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, @var{coorsys})
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, @var{coorsys}, @var{dir})
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "data")
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "data", "z")
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "data", "x")
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "data", "y")
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "data", [@var{x} @var{y} @var{z}])
+## @deftypefnx {} {} camorbit (@var{theta}, @var{phi}, "camera")
+## @deftypefnx {} {} camorbit (@var{hax}, @dots{})
+## Rotate the camera up/down and left/right around its target.
+##
+## Move the camera @var{phi} degrees up and @var{theta} degrees to the right,
+## as if it were in an orbit around its target.
+## Example:
+## @example
+## @group
+## @c doctest: +SKIP
+## sphere ()
+## camorbit (30, 20)
+## @end group
+## @end example
+##
+## These rotations are centered around the camera target
+## (@pxref{XREFcamtarget,,camtarget}).
+## First the camera position is pitched up or down by rotating it @var{phi}
+## degrees around an axis orthogonal to both the viewing direction (specifically
+## @code{camtarget() - campos()}) and the camera ``up vector''
+## (@pxref{XREFcamup,,camup}).
+## Example:
+## @example
+## @group
+## @c doctest: +SKIP
+## camorbit (0, 20)
+## @end group
+## @end example
+##
+## The second rotation depends on the coordinate system @var{coorsys} and
+## direction @var{dir} inputs.
+## The default for @var{coorsys} is @qcode{"data"}.  In this case, the camera is
+## yawed left or right by rotating it @var{theta} degrees around an axis
+## specified by @var{dir}.
+## The default for @var{dir} is @qcode{"z"}, corresponding to the vector
+## @code{[0, 0, 1]}.
+## Example:
+## @example
+## @group
+## @c doctest: +SKIP
+## camorbit (30, 0)
+## @end group
+## @end example
+##
+##
+## When @var{coorsys} is set to @qcode{"camera"}, the camera is moved left or
+## right by rotating it around an axis parallel to the camera up vector
+## (@pxref{XREFcamup,,camup}).
+## The input @var{dir} should not be specified in this case.
+## Example:
+## @example
+## @group
+## @c doctest: +SKIP
+## camorbit (30, 0, "camera")
+## @end group
+## @end example
+## (Note: the rotation by @var{phi} is unaffected by @qcode{"camera"}.)
+##
+## The @code{camorbit} command modifies two camera properties:
+## @pxref{XREFcampos,,campos} and @pxref{XREFcamup,,camup}.
+##
+## By default, this command affects the current axis; alternatively, an axis
+## can be specified by the optional argument @var{hax}.
+##
+## @seealso{camzoom, camroll}
+## @end deftypefn
+
+
+function camorbit (varargin)
+
+  [hax, varargin, nargin] = __plt_get_axis_arg__ ("camorbit", varargin{:});
+
+  if (nargin < 2 || nargin > 4)
+    print_usage ();
+  endif
+
+  theta = varargin{1};
+  phi = varargin{2};
+  if (! (isnumeric (theta) && isscalar (theta)
+         && isnumeric (phi) && isscalar (phi)))
+    error ("camorbit: THETA and PHI must be numeric scalars")
+  endif
+
+  if (nargin < 3)
+    coorsys = "data";
+  else
+    coorsys = varargin{3};
+    if (! any (strcmpi (coorsys, {"data" "camera"})))
+      error ("camorbit: COORSYS must be 'data' or 'camera'")
+    endif
+  endif
+
+  if (nargin < 4)
+    dir = "z";
+  else
+    if (strcmpi (coorsys, "camera"))
+      error ("camorbit: DIR must not be used with 'camera' COORSYS.");
+    endif
+    dir = varargin{4};
+  endif
+
+  if (ischar (dir))
+    switch tolower (dir)
+      case "x"
+        dir = [1 0 0];
+      case "y"
+        dir = [0 1 0];
+      case "z"
+        dir = [0 0 1];
+      otherwise
+        error ("camorbit: DIR must be 'x', 'y', 'z' or a numeric 3-element \
+                vector.");
+    endswitch
+  endif
+  if (! (isnumeric (dir) && numel (dir) == 3))
+    error ("camorbit: DIR must be 'x', 'y', 'z' or a numeric 3-element \
+            vector.");
+  endif
+
+  if (isempty (hax))
+    hax = gca ();
+  else
+    hax = hax(1);
+  endif
+
+  view_ax = camtarget (hax) - campos (hax);
+  view_ax /= norm (view_ax);
+  ## orthogonalize the camup vector
+  up = camup (hax) - view_ax*dot (camup (hax), view_ax);
+  up /= norm (up);
+  pitch_ax = cross (up, view_ax);
+
+  if (strcmpi (coorsys, "camera"))
+    yaw_ax = up;
+  else
+    yaw_ax = dir;
+  end
+
+  ## First pitch up then yaw right (order matters)
+  pos = num2cell (campos (hax));
+  [pos{:}] = __rotate_around_axis__ (pos{:}, phi, pitch_ax, camtarget (hax));
+  [pos{:}] = __rotate_around_axis__ (pos{:}, theta, yaw_ax, camtarget (hax));
+  pos = [pos{:}];
+
+  up = num2cell (up);
+  [up{:}] = __rotate_around_axis__ (up{:}, phi, pitch_ax, [0 0 0]);
+  [up{:}] = __rotate_around_axis__ (up{:}, theta, yaw_ax, [0 0 0]);
+  up = [up{:}];
+
+  camup (hax, up)
+  campos (hax, pos)
+
+endfunction
+
+
+%!demo
+%! peaks ();
+%! ## rotate the camera upwards
+%! camorbit (0, 30);
+%! ## rotate the camera right
+%! camorbit (20, 0);
+
+
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   sphere ();
+%!   campos ([20 0 0]);
+%!   camorbit (0, 60);
+%!   p = campos ();
+%!   u = camup ();
+%!   assert (p, [10 0 sqrt(3)*10], -eps);
+%!   assert (u, [-sqrt(3)/2 0 0.5], -eps);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect
+
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   sphere ();
+%!   camorbit(20, 30, "camera")
+%!   p = campos ();
+%!   u = camup ();
+%!   ## Matlab 2008a
+%!   pm = [-0.724972932190484  -9.37224596596009  14.5476946558943];
+%!   um = [0.375634339316796  0.77045096344497  0.515076844803523];
+%!   assert (p, pm, -5e-15);
+%!   assert (u, um, -5e-15);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect
+
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   sphere ();
+%!   camorbit(20, 30, "data", [1 2 3]);
+%!   p = campos ();
+%!   u = camup ();
+%!   ## Matlab 2014a
+%!   pm = [-0.215772672525099  -9.04926615428815  14.7669978066852];
+%!   um = [0.413058199972826  0.773801198226611  0.48022351989284];
+%!   assert (p, pm, -5e-15);
+%!   assert (u, um, -5e-15);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect
+
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   sphere ();
+%!   camorbit (54, 37);
+%!   p = campos ();
+%!   u = camup ();
+%!   va = camva ();
+%!   ## Matlab 2014a
+%!   pm = [1.92211976102821  -6.48896756467585  15.9436117479337];
+%!   um = [-0.261437503254928  0.882598219532154  0.390731128489274];
+%!   vam = 10.1274850414735;
+%!   assert (p, pm, -5e-15);
+%!   assert (u, um, -5e-15);
+%!   assert (va, vam, -5e-15);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect
+
+## another figure, test hax
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   hax = subplot (1, 2, 1);
+%!   sphere (hax1);
+%!   x = campos ();
+%!   camorbit (20, 30)
+%!   subplot (1, 2, 2);
+%!   sphere ();
+%!   camorbit (hax, -20, -30)
+%!   y = campos (hax);
+%!   assert (x, y, -eps);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect
+
+## Test input validation
+%!error <numeric scalars> camorbit ([1 2], [3 4])
+%!error <Invalid call> camorbit (1, 2, "data", "z", 42)
+%!error <DIR must be> camorbit (1, 2, "data", "meh")
+%!error <DIR must be> camorbit (1, 2, "data", [1 2 3 4])
+%!error <DIR must not be> camorbit (1, 2, "camera", "x")
+%!error <COORSYS must be> camorbit (1, 2, "meh")

--- a/scripts/plot/appearance/camroll.m	Sat Sep 30 14:53:30 2017 -0500
+++ b/scripts/plot/appearance/camroll.m	Thu Jul 14 22:24:05 2016 -0700
@@ -52,7 +52,7 @@
 ## By default, these commands affect the current axis; alternatively, an axis
 ## can be specified by the optional argument @var{ax}.
 ##
-## @seealso{camzoom, camup}
+## @seealso{camzoom, camorbit, camup}
 ## @end deftypefn
 
 

--- a/scripts/plot/appearance/camzoom.m	Sat Sep 30 14:53:30 2017 -0500
+++ b/scripts/plot/appearance/camzoom.m	Thu Jul 14 22:24:05 2016 -0700
@@ -50,7 +50,7 @@
 ## By default, these commands affect the current axis; alternatively, an axis
 ## can be specified by the optional argument @var{ax}.
 ##
-## @seealso{camroll, camva}
+## @seealso{camroll, camorbit, camva}
 ## @end deftypefn
 
 

--- a/scripts/plot/appearance/module.mk	Sat Sep 30 14:53:30 2017 -0500
+++ b/scripts/plot/appearance/module.mk	Thu Jul 14 22:24:05 2016 -0700
@@ -14,6 +14,7 @@
   %reldir%/axis.m \
   %reldir%/box.m \
   %reldir%/campos.m \
+  %reldir%/camorbit.m \
   %reldir%/camroll.m \
   %reldir%/camtarget.m \
   %reldir%/camup.m \